The response to local anaesthetics (EMLA-cream) as a clinical test to diagnose between hypermobility and Ehlers Danlos type III syndrome.

To make a differential diagnosis of Ehlers Danlos (EDS) Type III syndrome and Hypermobile patients has been difficult. In genetic advising and prognosis of the EDS patients there are need for new tools to separate them from hypermobile patients. Topical analgesics (EMLA cream) was applied to seven EDS patients, ten hypermobile patients, and to fifteen controls. The analgesic efficacy of cutaneous analgesia was evaluated by sensory and pain thresholds to brief argon laser stimuli, and the depth of the cutaneous analgesia was measured by sensory and pain threshold depth to controlled needle insertions. Controls and hypermobiles did not differ in their response to cutaneous analgesia. The thresholds to cutaneous laser stimulation and the depth of analgesia increased significantly less in the Ehlers Danlos patients compared to the other two groups. In clinical practice a needle insertion test can easily be applied to investigate if patients are responders or non-responders to local analgesics.